1. Field of the Invention
This invention relates generally to force-applying devices. More particularly, it relates to a clamping device designed to facilitate coil-winding operations. The invention is a result of a contract with the United States Department of Energy.
2. Related Art
This invention was developed to overcome problems encountered in producing a generally D-shaped helical coil by winding a copper conductor about the hub of a suitable frame, or bobbin. The conductor to be so wound was a copper bar of oblong cross-section, one edge-face of the bar being provided with adherent non-conductive pads for ensuring a selected between-turn spacing between the turns of the coil. Winding was conducted by securing an end of the conductor to an upper part of the hub and then rotating the bobbin about a vertical axis to wind the conductor downwardly about the hub. Several conventional clamping assemblies were mounted to the bobbin at selected points about the circumference of the hub to expedite winding. Each assembly included a frame carrying three manually operated clamps of the toggle type. The clamping assemblies were provided to serve two principal functions. First, after the laydown of a typical turn of the coil, the assemblies were used to force that turn upwardly against the previously formed turn to reduce the spacing therebetween to the value set by the pads. Second, the assemblies then were repositioned and used to apply radial force to all of the turns formed thus far, to press them against the hub. In the course of winding any given turn, each of the clamping assemblies had to be completely removed from the bobbin temporarily to make way for the conductor. The clamping assemblies were generally unsatisfactory. As indicated above, they required frequent repositioning and removal, and they did not permit continuous winding. Furthermore, it was difficult for one operator to remove and re-install a clamping assembly.